My son is 5 yrs old and his real father has never paid child support and has not made any kind of attempt to be in his life. We signed child support papers in dec 04 and he dropped off the face of the earth after that. I have not heard a single word from him nor have I seen a check. I am married now and my husband would like to adopt him. I would like to know if I can file for child abandonment and how do I do it? I live in Texas. Please help??

This is the statue for termination of parental rights in Texas. A lawyer would have to determine if your specific case qualifies for "extreme parental disinterest". Once termination is determined to be justified then your husband can adopt. It would all be done simultaneously. From what I have read it sounds as if what your ex has done would qualify but you would need to talk to a lawyer to be sure.
Texas

Statute: §§161.001; 161.003(a)

Grounds: Abandonment or extreme parental disinterest, abuse/neglect, mental illness or deficiency, alcohol or drug induced incapacity, felony conviction/incarceration, failure of reasonable efforts, sexual abuse, abuse/neglect or loss of rights of another child, failure to maintain contact, failure to provide support, child’s best interest, felony assault of child or sibling, murder/manslaughter of sibling child, refusal to submit to court order, failure to provide education, voluntary relinquishment, drug or alcohol addicted newborn.